Chain wrench



April 14, 1970 v. M. OCKINGA CHAIN WRENCH Filed Oct. 24, 1967 b I I I ll Virgil M Ockinga I NVEN TOR.

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United States Patent 3,505,914 CHAIN WRENCH i Virgil M. Ockinga, Morrill, Nebr. 68824 (G.D., Cairo, Nebr.) Filed Oct. 24, 1967, Ser. No. 677,518 Int. Cl. B25b 13/52 US. Cl. 81-66 9 Claims ABSTRACT OF THE DISCLOSURE A chain wrench for pipe in which an arcuate jaw extending laterally from the wrench handle is spaced throughout from the pipe by pipe gripping elements projecting from the link chain. The jaw thus provides backing for the chain when engaged with a pipe for fa substantial circumferential distance about the pipe. A spring-biased hook slidably mounted on the handle maintains tension on the chain when engaged with the pipe.

This invention relates to pipe wrenches of the flexible chain type.

Pipe wrenches of the foregoing type are of course well known and particularly useful for turning of objects such as pipes that are relatively inaccessible to the jaws of the more common types of wrenches. However, one of the problems encountered when using a chain type of pipe wrench, is damage caused to the pipe because of the concentration of the pipe gripping forces. Another problem in connection with chain types of wrenches, is to maintain the proper tension on the link chain.

An important object of the present invention therefore is to provide a chain type of pipe wrench wherein a more even distribution of pipe gripping forces is assured in order to avoid damage to the pipe. Further, despite the small variations in pipe diameters, the proper chain tension will be applied.

In accordance with the present invention, the chain wrench is provided with an arcuate jaw which extends a substantial distance laterally of the longitudinal wrench handle in order to provide an arcuate backing for a substantial length of chain while embracing the pipe. The chain is permanently and pivotally connected to one arcuate end of the jaw and slidably received through the other end. The chain extends from an outlet guide portion in the jaw parallel to the wrench handle and is engaged by a spring-biased hook slidably mounted on the wrench handle for this purpose. Thus, the chain is engaged with the pipe under the proper tension without requiring any adjustment of the wrench on the part of the operator. Further, the link chain is provided with gripping elements that project radially inwardly from the jaw.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view showing the chain wrench of the present invention.

FIG. 2 is a top plan view of the forward portion of the wrench in engagement with a pipe.

FIG. 3 is a side sectional view taken substantially through a plane indicated by section line 3-3 in FIG. 2.

FIG. 4 is a transverse sectional view taken substantially through a plane indicated by section line 4-4 in FIG. 3.

FIG. 5 is a partial side elevational view of a modified form of wrench.

Referring now to the drawings in detail, it will be observed that the wrench generally referred to by reference numeral consists of an arcuate jaw 12, an elongated 3,505,914 Patented Apr. 14, 1.970

handle 14 and a link chain 16. An object such as the pipe 18 is adapted to be engaged by the wrench by wrapping the chain 16 thereabout after which it is inserted through the jaw 12 and yieldably anchored to the wrenchhandle 14 by means of the anchoring hook assembly 20 slidably mounted on the wrench handle.

The jaw 12 is generally arcuate in shape and extends laterally of the handle 14 to which it is connected by being integrally formed therewith for example. A pin 22 pivotally connects one end of the link chain 16 to the jaw adjacent the end 24. The jaw includes two parallel spaced sidewall portions 26 between which the chain is slidably received along the arcuate backing portion 28. Thus, the chain is inserted into the jaw at the inlet end 30 thereof opposite the end 24 and extends out of the jaw over the rounded guide portion 32 closely spaced from the pivotal connecting pin 22. The chain extends from the jaw generally parallel to the wrench handle and is releasably anchored thereto by means of the hook assembly 20.

The hook assembly includes a channel-shaped slide member 34 having inturned lugs 36 as shown in FIG. 4, slidably received in slide grooves 38 formed in the handle for this purpose. Accordingly, the hook assembly is displaceable along the handle generally parallel to its longi-.

tudinal axis. Enclosed within the slide member 34, is a spring 38 which reacts between the shoulder portion 40 on the handle and the end portion 42 of the slide member as shown in FIG. 3 in order to continuously bias the hook assembly in a direction away from the jaw 12. A hook formation 44 projects from the slide member and is adapted to engage between the links of the chain in order to apply tension to the chain when embracing the pipe 18.

Except for the gripping elements 46 projecting from one side of the chain links 48, the chain 16 is of conventional construction. The jaw 12 is dimensioned as more clearly seen in FIG. 3 so that when the chain extends therethrough, the gripping elements will space the jaw from the pipe. Thus, engagement between the jaw and the pipe is avoided, the jaw acting only to anchor one end of the chain and back a substantial circumferential portion of the chain in engagement with the pipe in order to more uniformly distribute the gripping forces exerted on the pipe by the chain. Toward this end, it will be observed that the jaw 12 extends between the ends 24 and 30 a distance exceeding an arc of degrees relative to the center of curvature of the jaw.

In order to facilitate pulling of the chain 16, a handle 50 is secured to the end link. Also, to facilitate insertion of the chain through the arcuate jaw, a slot 52 may be provided in one of the side walls as shown in FIG. 5. This form of the invention may be more suitable for smaller size wrenches and where working space is very limited.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. A chain wrench comprising a jaw, an elongated handle rigidly connected to said jaw having a longitudinal axis, a link chain, means pivotally and permanently connecting the link chain to said jaw at a fixed pivot point laterally spaced from the longitudinal axis of the handle, means for slidably receiving the link chain through the jaw including an inlet end and a guide portion from which the link chain extends along the handle in spaced relation to said pivotal connecting means, and releasable engaging means movably mounted on the handle for yieldably anchoring the link chain to the handle in longitudinal spaced relation to the jaw.

2. The combination of claim 1 including gripping elements on the link chain projecting radially inwardly from the jaw when the chain is in the slidable receiving means.

3. The combination of claim 2 wherein said releasable engaging means comprises a hook engageable with the chain, means slidably mounting the hook on the handle for displacement substantially parallel thereto, and spring means biasing the hook in a direction away from the jaw.

4. The combination of claim 3 wherein said jaw is arcuate and has a center of curvature fixedly spaced from the handle, the jaw extending from said inlet end of the slidable receiving means to the pivotal connecting means through an angle exceeding 90 degrees relative to the center of curvature.

5. The combination of claim 1 wherein said releasable engaging means comprises a hook engageable with the chain, means slidably mounting the hook on the handle for displacement substantially parallel thereto, and spring means biasing the hook in a direction away from the jaw.

6. The combination of claim 1 wherein said jaw is arcuate and has a center of curvature fixedly spaced from the handle, the jaw extending from said inlet end of the slidable receiving means to the pivotal connecting means through an angle exceeding 90* degrees relative to the center of curvature.

7. The combination of claim 6- including gripping elements on the link chain projecting substantially toward said center of curvature from the arcuate jaw when the chain is in the slidable receiving means.

8. A chain wrench for engaging a pipe comprising an arcuate jaw, an elongated handle rigidly connected to said jaw, a link chain, means pivotally connecting the link chain to said jaw laterally spaced from the handle, guide means for slidably receiving the link chain through the jaw, a hook engageable with the chain externally of the handle, means slidably mounting the hook on the handle for displacement substantially parallel thereto, and spring means biasing the hook in a direction away from the jaw.

9. The combination of claim 8 including gripping means mounted on the chain projecting from the jaw for spacing the same throughout from the pipe when engaged therewith.

References Cited UNITED STATES PATENTS 1,063,153 5/ 1913 Benedict 81-67 1,792,401 2/ 1931 Sorensen et al 81-69 X 1,096,382 5/1914 McLeod 81-69 2,665,604 1/ 1954 Robertson 8 166 1,010,232 11/1911 Chipchase et al 8l-67 2,970,501 2"/ 1961 Miller 8170 X FOREIGN PATENTS 10,569 12/ 1932 Australia.

JAMES L. JONES, 1a., Primary Examiner US. Cl. X.R. 81-68 

